also: あなじゃこ
noun
Japanese mud shrimp (Upogebia major)
A species of mud shrimp found in Japan. The name is usually written in katakana.
干潟でアナジャコの巣穴を見つけた。
I found a Japanese mud shrimp burrow on the tidal flat.
Compound of 穴 (ana, 'hole') and 蝦蛄 (shako, 'mantis shrimp'), referring to its burrowing habit. The exact derivation is uncertain.